The role of bone marrow evaluation in the staging of patients with otherwise localized, low-risk neuroblastoma

Bone Marrow Involvement in Neuroblastoma: A Study of Hemato-morphological Features

Bone marrow involvement in neuroblastoma indicates advanced stage of disease. The recent use of autologous bone marrow "rescue", has provided an additional important reason for accurate assessment of bone marrow status in newly diagnosed patients. In this study, we analyzed 44 cases of neuroblastoma for bone marrow infiltration status and their hematological parameters. Eighty-eight bone marrow aspirate and trephine touch imprint smears and 44 trephine biopsy sections were examined in these 44 patients. Of these, 24 cases (54.5 %) showed marrow infiltration. Leucopenia and bicytopenia were significantly (p < 0.05) associated with marrow infiltration. Both bone marrow aspirate and biopsy were positive for infiltration in 16 out of 24 positive cases. Only aspirate smears were positive in 4 and only trephine biopsy in another 4 cases. The pattern of infiltration consisted of rosette formation in 40.7 % cases on aspirate smears and 22.2 % cases in trephine biopsies. Remaining cases showed diffuse and interstitial presence of tumor cells and cases positive only on trephine biopsy, showed marked stromal reaction. Bilateral trephine biopsies combined with aspirate smears picked up all positive cases compared to when they were assessed alone.

Identification of novel prognostic markers in relapsing localized resectable neuroblastoma

Patients with localized resectable neuroblastoma (NB) generally have an excellent prognosis and can be treated by surgery alone, but approximately 10% of them develop local recurrences or metastatic progression. The known predictive risk factors are important for the identification of localized resectable NB patients at risk of relapse and/or progression, who may benefit from early and aggressive treatment. These factors, however, identify only a subset of patients at risk, and the search for novel prognostic markers is warranted. This review focuses on the recent advances in the identification of new prognostic markers. Recently we addressed the search of novel genetic prognostic markers in a selected cohort of patients with stroma-poor localized resectable NB who underwent disease relapse or progression (group 1) or complete remission (group 2). High-resolution array-comparative genomic hybridization (CGH) DNA copy-number analysis technology was used. Chromosome 1p36.22p36.32 loss and 1q22qter gain, detected almost exclusively in group 1 patients, were significantly associated with poor event-free survival (EFS). Increasing evidence points to anaplastic lymphoma kinase (ALK) as a fundamental oncogene associated with NB. The immunohistochemical analysis of sporadic NB localized resectable primary tumors (stage 1-2) showed a correlation between aberrant ALK level of expression and tumor progression and clinical outcome. Moreover, other factors that might influence the clinical behavior of these tumors will be reviewed.

Detection of GD2-positive cells in bone marrow samples and survival of patients with localised neuroblastoma

The impact of bone marrow (BM) GD2-positive cells on survival has been evaluated in 145 Italian children with localised neuroblastoma (NB) evaluated at diagnosis by anti-GD2 immunocytochemistry. Nineteen of these (13.1%) were found to be BM GD2-positive, with the number of positive cells ranging between 1 and 155 out of 1 × 10⁶ total cells analysed. Seven/19 (38.8%) GD2-positive vs 12/126 (9.5%) GD2-negative patients relapsed. The 5-year event-free survival (EFS) and overall survival of the GD2-positive patients was significantly worse than that of the GD2-negative ones (62.2 vs 89.9%, P<0.001; and 74.9 vs 95.9%, P=0.005, respectively). GD2 positivity was not associated to other known risk factors, and in particular to Myc-N amplification and 1p deletion. Among Myc-N-negative patients, the EFS of those negative for both GD2 and 1p deletion was significantly better than in children positive for either one of these two markers (EFS=96.9 vs 66.0%, P<0.001). In conclusion, GD2 positivity may represent a prognostic marker for patients with non-metastatic NB without Myc-N amplification, and its combination with genetic alterations might help identifying patients that require a more careful follow-up.

Metastatic tumors in bone marrow: histopathology and advances in the biology of the tumor cells and bone marrow environment

The nonhematopoietic tumors most often diagnosed in the bone marrow are metastatic. Currently, accurate diagnosis of tumor metastasis requires integration of the clinical findings; morphological features; and results of immunohistochemical stains, cytogenetics, and molecular studies. This review focuses on a practical approach to the diagnosis of metastatic tumors in the bone marrow according to current standards of practice and discusses recent advances in understanding of tumor metastasis and the interaction between tumors and the bone marrow environment.